– Place garlic, shallots, lemon grass, turmeric, galangal powder, chillies and 1/4 teaspoon each salt and pepper in a food processor.
– Process until a paste forms, adding oil to assist grinding process.
– Cut fish into large bite-sized pieces.
– Place fish in a bowl with spice paste, toss well, and cover; refrigerate for 15 minutes then place on a foil-lined grill tray.
– Cook under a broiler for 3-4 minutes, turning pieces over so fish browns on all sides.
– Arrange fish on a serving plate and sprinkle with fish sauce.